Explanation of the simulation. (a) Cartoon of the two models, Sticky (left)
and Patch (right). In the Sticky model, telomeres (circles) collide and
coalesce until the bouquet is complete (all telomeres have coalesced into one
cluster). In the patch model, telomeres move along the surface until they
encounter the bouquet site (shading), at which point they cease motion. (b)
Schematic of two steps of a telomere in the simulation. The telomere at
T0 takes one step anywhere within the circle defined by the maximum
distance (Dmax). The direction of motion is chosen by the angle
θ. The probability of choosing a given θ is governed by the bias
value (see c below). At T1, the bounding circle has shifted, a new
θ is chosen, and another step is taken. (c) Illustration of the effect
of increasing bias on the direction of motion of telomeres in the simulation.
For ease of illustration the space of possible angles is divided into 10
wedges, and the probability of choosing a step into a given wedge is indicated
by shade; the actual probabilities in the simulation are continuous.
Probabilities were calculated by simulating 106 total steps for
each bias value. With zero bias (left), the probability of choosing any
direction is the same. Increasing the bias to 0.54 (center) results in a very
slight increase in the probability of motion toward the bouquet pole, but
allows normal bouquet completion for D = 2.4 μm2/s. A
bias value of 10.0 (right) moves telomeres almost directly toward the South
pole and allows timely bouquet completion with much lower diffusion
constants.